MG996R Servo · Round Horn

High-torque metal-gear analog servo delivering up to 11 kgf·cm of stall torque at 6V under standard 50 Hz PWM control.

What is the MG996R Servo · Round Horn?

The MG996R is TowerPro's high-torque analog servo, the metal-gear upgrade to the popular MG995 class. This round-horn variant ships with a circular output disc and delivers a stall torque of about 9.4 kgf·cm at 4.8V and 11 kgf·cm at 6V, packed into a standard 40.7 x 19.7 x 42.9 mm case weighing roughly 55 g.

It uses the same three-wire interface as any hobby servo: VCC, GND, and a PWM signal line. Position is set by a 50 Hz pulse train (20 ms period) whose high time runs from about 1 ms to 2 ms, mapping across the servo's travel with a 5 microsecond dead band. Internally, a full metal gear train and dual ball bearings on the output shaft give it more durability and load capacity than plastic-gear servos.

The tradeoff for that torque is current. Running current sits in the hundreds of milliamps and stall current can reach about 2.5 A at 6V, so the MG996R needs a dedicated power supply rather than the host board's onboard regulator. Rated operating voltage spans 4.8V to 7.2V, with an operating temperature range of 0 to 55 degrees C.

MG996R Servo · Round Horn pinout

Pin	Function	Type
`VCC` VCC (4.8-7.2V)	Power	Power in
`GND` GND	Power	Power in
`SIG` PWM Signal	PWM servo control pulse	Digital input

Specifications

Operating voltage: 6 V (max 7.2 V)
Interface: GPIO timing (Trigger / Echo)
Dimensions: 40.7 × 42.9 × 19.7 mm

Verified from the Tinkered component library · TowerPro.

Circuit requirements

Power VCC from a dedicated 5-6V supply sized for the load, not the Arduino 5V pin: stall current can hit ~2.5A at 6V and will brown out or reset the board.
Tie the external supply ground to the Arduino ground so the PWM signal shares a common reference; a floating ground gives erratic or no motion.
Keep VCC within the 4.8-7.2V rating. A 2S LiPo (7.4V nominal, up to 8.4V charged) exceeds the maximum and can damage the servo.
Drive the SIG line with a standard 50 Hz servo PWM pulse (about 1-2 ms high time). The signal is logic-level and works from 3.3V or 5V microcontroller outputs.
Add a bulk electrolytic capacitor (470-1000 uF) across the servo supply near the connector to absorb inrush and motion current spikes that otherwise cause jitter and voltage sag.
No external flyback diode is required: the servo has its own internal motor driver and control electronics behind the three-wire interface.

Board compatibility

The MG996R Servo · Round Horn connects to any of the microcontrollers supported in Tinkered. Mind the 6 V logic level on 3.3 V boards.

Common MG996R Servo · Round Horn mistakes

Powering it from the Arduino 5V pin

The onboard regulator cannot supply the MG996R's stall current of around 2.5A. Doing so sags the rail and randomly resets the board. Use a separate 5-6V supply.

Forgetting the common ground

When the servo runs off its own supply, the supply ground must connect to the controller ground. Without a shared reference the PWM signal is meaningless and the servo twitches or stays dead.

Overvolting with a 2S LiPo

The absolute maximum is 7.2V. A charged 2S pack reads up to 8.4V, over the rating, and can cook the servo electronics. Use a 5-6V regulated supply or a UBEC.

Assuming a full, precise 180 degrees

As an analog servo the MG996R's reliable travel is closer to about 120 degrees, and unit-to-unit endpoints vary. Commanding hard 0 or 180 can drive it into the mechanical stops and stall, drawing peak current.

Ignoring jitter from a weak supply

Long, thin power leads and no decoupling capacitor let motion current spikes drop the rail, causing buzzing and hunting. Use adequate wire gauge and a bulk capacitor at the servo.

MG996R Servo · Round Horn datasheet

Official MG996R Servo · Round Horn datasheetTowerPro

Popular MG996R Servo · Round Horn projects

Robotic arm joints

The high metal-gear torque makes the MG996R a common choice for shoulder and elbow joints on multi-axis desktop arms and grippers.

Pan-tilt camera mount

A pair of MG996R servos builds a sturdy two-axis pan-tilt head for cameras, sensors, or laser turrets.

RC steering and throttle linkage

Its torque and metal gears hold up to the shock loads of RC car steering and large control surfaces.

Walking robot legs

Hexapod and quadruped builds use banks of MG996R servos for leg actuation where each joint must lift chassis weight.

Build with the MG996R Servo · Round Horn.

Drop the MG996R Servo · Round Horn into a circuit, write firmware, and simulate it in your browser, then deploy to real hardware. All in one editable Tinkered project.

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